This nonprovisional application was derived from the evolution of the idea exposed in the patent AR No. 254463 filed on Dec. 28, 1992 and patent No. WO/14355, filed Dec. 28, 1993 by the same inventor. In this machine a total novel hair-plucker head is presented.
The present invention is related to a personal depilatory device for removing human body hair that comprises a housing conformed as a handle and as minimum mounted in the interior, an electric micro-motor, a mechanism converter of rotation in straight reciprocating motion and a rotary hair-plucker head that exhibits, externally of said housing, the active part that performs the depilation when taking contact with the hair to extirpate.
In the previous art several types of depilatory apparatuses are known. The first ones, of manual operation, have been displaced by the modern devices operated by means of electric motors as described in U.S. Pat. Nos. 4,524,722 and 4,931,054. These devices present hair-plucker head whose depilatory elements are composed mainly of a cylindrical helical spring or a cylinder of flexible or elastic material, bent in arch form in their assemblies in a such way that present a multiple quantity of peripheral grooves recipients of the hair, that operate as continuous pincers of extirpation when closing.
The apparatuses that possess said depilatory elements with curved axis of rotation, are limited in the rotary speed of the hair-plucker and the extraction of hair becomes slow and consequently a painful operation. A painless depilation is one of the most important quality that should hold a depilatory machine and this problem has not been totally resolved by the previous art. Some well-known depilatory apparatuses, although are conformed by hair-plucker head of high-speed and straight axis of rotation, however their construction is very complex and production becomes very expensive. Another inconvenience that present some of the devices of the previous art is due to the loop of the depilatory element built with a metallic wire of round section, catch the hair also of circular section, in two contact points only: if the applied clamping pressure is excessive, it can cut the hair without extirpating it and if the pressure is scanty, the hair disengages, but the tug produces a painful sensation.
A system different from the previously mentioned has been proposed in the French patent FR No. 2,334,320. This describes a depilatory device that uses two helical springs diametrically opposed and that are simultaneously impelled in rotation and reciprocally compressed and extended by means of cams. This apparatus is of a very complex and expensive construction; the design type also limits the rotating speed, that makes the depilation slow and painful. According to declaration of the inventor of the patent EP 0386327 A2, the apparatus has not reached the market for those limitations.
For all those records it would be desirable to obtain a depilatory machine of motorized type of simple construction, portable, personal and usable in any place of economic cost of production. It would be desirable also to provide a depilating machine with the maximum extirpation speed possible, to reduce the pain of the depilation.
The present invention provides several new and original elements and improvements comparing with the devices of the previous art, what make simpler and more economic its production with an important increase of the manufacturing efficiency, like it will be described next.
The main improvements are obtained especially with the application of novel type of depilation hair-plucker head, comprising two helicoids sets conforming continuous tweezers, said helicoids mounted parallel disposed in a central rotatable shaft and fixed to it for rotation, in interleaved fashion and opposition so as to be parallel to one another and perpendicular to said central shaft with arranged helicoidal spaces as to define hair trap gaps between them and identified in accordance to the partially independent function accomplished as rotary-helicoid set, the one that only rotates and roto-reciprocating-helicoid set, the other one that rotates together and reciprocates in opposition to said first set. Said rotary hair-plucker head in its preferred embodiment is conformed by two helicoid sets made of metal, plastic, or another material, presenting the assembly a cylindrical form in the entire length.
Said depilation hair plucker head is made with the rotary-helicoid set incorporated to said central shaft and said roto-reciprocating-helicoid is interleaved coupled to set through its central hole by turning it as a screw and later enforced to rotation and free for reciprocating shifting by roller balls introduced in adecuate cavities of said shaft. As said, the rotary-helicoid set only rotate and said roto-reciprocating-helicoid set can shift reciprocally either way against opposing adjacent helicoidal surfaces in the axial direction so that helicoidal clamping gaps close twice in a reciprocating cycle. This is another important advantage fulfilled by this type of hair plucker head, obtained by clamping and extirpating superfluous hair twice each cycle. The number of clamping is dependent of the reciprocating cycles applied to the hair plucker head so as an additional improved performance is obtained increasing the quantity of clamping cycles, increasing the ratio per turn of continuous tweezers closures and the performance in the extraction of hair.
Another important improvement provided by the new types of helicoid tweezer of the hair-plucker head consists in the hair to depilate enters in the helicoidal openings and it is caught among the lateral faces of the helicoids, with lineal contact in the whole longitude holding it more firmly, avoiding the cutting.
Other of the most relevant advantages, purpose of the present invention, is provided by the straight axis of rotation and enforced cam follower that closes the tweezer, suitable for operating this depilatory device at relatively high speed unlike the prior art devices using spring return cam follower, noisy and requiring higher power consumption. A reciprocating converter transforms the motor rotation in straight reciprocation supplied to said roto-reciprocating helicoid set.
In accordance with the enunciated requirements, a favorite realization of the invention consists on a personal depilatory device for plucking superfluous human hair comprising, a housing conformed as handle, a hair-plucker head that exhibits externally an exposed portion which will contact the skin and the hair to extirpate.
Said depilatory hair-plucker head is formed by two different sets of helicoids, one with a pulley mounted in one end for rotation and the other mounting a collar for free rotation and reciprocating motion in the other end, both rotating jointly at high speed. During the operation, simultaneously with the rotation of both, an alternative axial displacement of the roto-reciprocating-helicoid set takes place in a direction and in the opposite and push against the respective adjacent rotary-helicoid surfaces, exercising a tweezer action, closing and opening up simultaneously two continuous helicoidal gaps among helicoids. The hair that grows in the surface of the skin enter, is caught and extirpated of root, for the clip action and rotation of the hair plucker head.
The depilatory hair plucker head rotates by means of pulley and belt or optionally meshed spur gears, that link it with the motor in one end, and in the other end, the fork and collar in cooperation with the reciprocating converter operate the axial trip of roto-reciprocating-helicoid set.
Many other favorite realizations of personal depilatory devices can be easily assembled by anyone skilled in the art using this same depilatory hair-plucker head and the different reciprocating means already reported in the afore mentioned patent of this inventor.